A variety of compact support apparatuses, including head, limb and buttock rests, have been developed for leisurely relaxation. In particular, a number of head rests have been designed to be foldably compact during nonuse.
Richards, U.S. Pat. No. 2,502,752, has developed a head and limb rest which comprises a pair of rectangular frames and a pair of top and bottom fabric slings. The frames are unfolded to angularly extend apart. The pivotal rotation of the frames is restricted by a pair of break joint braces, oppositely secured to the respective frames. The break joint type braces lock in position when the frame is fully unfolded to act as a support feature for the head and limb rest.
Nelson et al., U.S. Pat. No. 3,002,201, has developed a head rest utilizing a pair of rectangular metal frames. Instead of utilizing a hinging means for the two frames, a biasing elastic band is secured between the ends of the respective upper and lower frame members to force the frames to unfold and which also keeps the frames joined.
Similar devices have been made for head and limb support which utilize rivets or nuts and bolts to serve as a hinging and pivoting means for the frames of the head rest. Marks, U.S. Pat. No. 2,197,343 has developed such a foldable head rest comprising two polygonal frames pivotally secured at their central narrower portion by a rivet or screw. Other head rests including those of Richards and Ross, U.S. Pat. No. 2,574,590 comprise additional hinging hardware or pivotal rivets and the like to secure multiple frames together.
Among the various head rests developed, only Richards provides for a locking means to prevent further expansion or unfolding of the head rest frames. With regard to most of the other devices, the supportive fabric panels provide the limitation or restriction of rotation of the frame members when the panels are tautly extended in the fully open position. This feature is shown on the head rests of Nelson et al. and Marks.
Recent developments in composites and plastics have provided for a lighter weight molded plastic rectangular frame in the present head rest invention which combines strength and resilient flexibility. Integrally formed hinging components within the frame members eliminate pivotally connecting screws and rivets as well. The frame members of the present invention incorporate integral stops to restrict unfolding and rotation of the frames and add support to the head rest during use.